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Strain relaxation in InGaN/GaN epilayers by formation of V‐pit defects studied by SEM, XRD and numerical simulations
Author(s) -
Stránská Matějová Jana,
Horák Lukáš,
Minárik Peter,
Holý Václav,
Grzanka Ewa,
Domagała Jaroslaw,
Leszczyński Michal
Publication year - 2021
Publication title -
journal of applied crystallography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.429
H-Index - 162
ISSN - 1600-5767
DOI - 10.1107/s1600576720014764
Subject(s) - reciprocal lattice , materials science , diffraction , relaxation (psychology) , crystallography , scanning electron microscope , strain (injury) , dislocation , transmission electron microscopy , epitaxy , condensed matter physics , layer (electronics) , optics , composite material , nanotechnology , chemistry , physics , medicine , psychology , social psychology
V‐pit defects in InGaN/GaN were studied by numerical simulations of the strain field and X‐ray diffraction (XRD) reciprocal space maps. The results were compared with XRD and scanning electron microscopy (SEM) experimental data collected from a series of samples grown by metal–organic vapor phase epitaxy. Analysis of the principal strains and their directions in the vicinity of V‐pits explains the pseudomorphic position of the InGaN epilayer peak observed by X‐ray diffraction reciprocal space mapping. The top part of the InGaN layer involving V‐pits relieves the strain by elastic relaxation. Plastic relaxation by misfit dislocations is not observed. The creation of the V‐pits appears to be a sufficient mechanism for strain relaxation in InGaN/GaN epilayers.